Supporting a large bow window in wall with cathedral ceiling

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Windows on Washington
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Re: Supporting a large bow window in wall with cathedral ceiling

#16 Post by Windows on Washington » Sat Jan 14, 2012 3:15 pm

Knee braces or some other sort of supplemental support are an absolute must.

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Re: Supporting a large bow window in wall with cathedral ceiling

#17 Post by JCRisn » Sat Jan 14, 2012 3:23 pm

Windows on Washington wrote:Wayne is referring to having the knee braces set a tiny bit higher so that as they settle out under the weight of the bow that they finish level.

Have the floor of the bow set about 1/8th bubble up on the level.
Oh, ok, I understand now. Thanks

So, apparently, no one has a concern with the cathedral ceiling and wall structure???

I have attached a photo to my original post (at top) of the front of the house where the window is going.

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Re: Supporting a large bow window in wall with cathedral ceiling

#18 Post by Windows on Washington » Sat Jan 14, 2012 3:44 pm

Should be fine.

Knee braces should take the brunt of the weight.

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Re: Supporting a large bow window in wall with cathedral ceiling

#19 Post by TheWindowNerd » Sun Jan 15, 2012 6:28 pm

No problem with the gable end install.
The projection past the edge of the slate may render knee braces unnessecary. it will depend on how far past the unit over hangs and how much the seat board can be supported by the masonary.
You do not have total wall depth including the masonary nor do you have a footprint of the new window. If you can not get those things and eval prior to install you will need to be ready to make a decision on the fly at time of install.

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Re: Supporting a large bow window in wall with cathedral ceiling

#20 Post by HomeSealed » Sun Jan 15, 2012 11:16 pm

anthony wrote:No problem with the gable end install.
The projection past the edge of the slate may render knee braces unnessecary. it will depend on how far past the unit over hangs and how much the seat board can be supported by the masonary.
You do not have total wall depth including the masonary nor do you have a footprint of the new window. If you can not get those things and eval prior to install you will need to be ready to make a decision on the fly at time of install.
I was thinking the same... After seeing the pic, it looks like a substantial portion (10", give or take) will be supported between the framing and masonry. Given the fact that it is a bow ( as opposed to a bay with an extended projection) knee braces may not be very practical or necessary.
I'd say that it really should be left up to the installer's discretion after seeing the pic.

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Re: Supporting a large bow window in wall with cathedral ceiling

#21 Post by randy » Mon Jan 16, 2012 10:20 am

I respectfully disagree. I would be concerned with putting any weight on the rock, since it is facade only. Any weight imposed on the rock could lead to mortar cracks down the road, not to mention sagging of the bow window. Obviously this is hypothetical to an extent, but this is the time to do it right, so I'd still go with knee bracing. This is one large (heavy) window unit.

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Re: Supporting a large bow window in wall with cathedral ceiling

#22 Post by HomeSealed » Mon Jan 16, 2012 11:27 am

I dont disagree that ideally you want the kneebracing, I just dont know how much room you will have left for them being that a bow isnt going to have much projection. Further, the knee braces would likely just be anchored into the masonry anyway, still putting the stress on it, albeit from a different angle.... I guess ultimately my take is that I could not make the call on it unless I was there installing it, knowing the exact specs, that why my bottom line is that it should be the installer's call. The manufacturer spec on the window will likely call for only one or the other (knees or cables/chains).
... After all, you did contract him (installer)to do the job, and to stand behind his work. As long as you've hired a reputable company, you should be able to hang your hat on that.

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Re: Supporting a large bow window in wall with cathedral ceiling

#23 Post by Windows on Washington » Mon Jan 16, 2012 11:50 am

Scribe out the knee brace on the masonry wall, take a diamond blade, cut back the rock in those locations and mount the knee brace directly to structure.

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Re: Supporting a large bow window in wall with cathedral ceiling

#24 Post by HomeSealed » Mon Jan 16, 2012 12:19 pm

JC, be sure to have your installer contact WoW if he has any issues when you insist on that procedure. :mrgreen:

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Re: Supporting a large bow window in wall with cathedral ceiling

#25 Post by TheWindowNerd » Mon Jan 16, 2012 4:55 pm

You can see there is difference among a very good group of guys.
As has been mentioned a lot in this case will be determined at the time of install.
Try and have a great relationship with the installers, make sure to offer them coffee or something, it goes along way.

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Re: Supporting a large bow window in wall with cathedral ceiling

#26 Post by Windows on Washington » Mon Jan 16, 2012 4:59 pm

HomeSealed wrote:JC, be sure to have your installer contact WoW if he has any issues when you insist on that procedure. :mrgreen:
:lol:

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Re: Supporting a large bow window in wall with cathedral ceiling

#27 Post by JCRisn » Tue Jan 17, 2012 2:30 pm

HomeSealed wrote:
anthony wrote:No problem with the gable end install.
The projection past the edge of the slate may render knee braces unnessecary. it will depend on how far past the unit over hangs and how much the seat board can be supported by the masonary.
You do not have total wall depth including the masonary nor do you have a footprint of the new window. If you can not get those things and eval prior to install you will need to be ready to make a decision on the fly at time of install.
I was thinking the same... After seeing the pic, it looks like a substantial portion (10", give or take) will be supported between the framing and masonry. Given the fact that it is a bow ( as opposed to a bay with an extended projection) knee braces may not be very practical or necessary.
I'd say that it really should be left up to the installer's discretion after seeing the pic.
The salesman and his installer said the window would NOT be supported by the stone. The installer even drew me a sketch showing how it would be supported. As mentioned before, they would attach the two sides and the bottom of the window to the wood framing and use cables. They were not going to use knee braces. When I told the salesman that I was asking advice on a forum and that you all said knee braces were required (or highly encouraged) then the salesman said, "we could put braces on if YOU wanted". If I wanted? If I wanted?? What about what is REQUIRED to support the window properly???

I asked about the projection. I can't remember exactly so I'll reply later with that.

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Re: Supporting a large bow window in wall with cathedral ceiling

#28 Post by Window4U (IL) » Tue Jan 17, 2012 3:36 pm

I've read all the posts a couple of times and the question I have that hasn't been talked about is how they are going to finish off the top? I would think a nice little roof would be proper, but with all this cable talk, are they just going to fabricate a collar all the way up to the gable soffit? That could end up pretty ugly if all they have planned is a coil stock collar.

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Re: Supporting a large bow window in wall with cathedral ceiling

#29 Post by Delaware Mike » Tue Jan 17, 2012 3:40 pm

I kind of assumed that some type of roof was going to be constructed with a price of $10K?

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Re: Supporting a large bow window in wall with cathedral ceiling

#30 Post by TheWindowNerd » Tue Jan 17, 2012 3:49 pm

I also assume a pent or hip roof.

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